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Atovaquone

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Atovaquone, Mepron

  • See Also
  1. Atovaquone/Proguanil
  • Indications
  1. Human Immunodeficiency Virus (HIV)
    1. Pneumocystis carinii Pneumonia prophylaxis
    2. Pneumocystis carinii Pneumonia treatment
      1. Patients unable to tolerate Bactrim
  2. Babesiosis (off-label)
  3. Toxoplasmosis in HIV Infection (off-label)
  • Contraindications
  1. Creatinine Clearance <30 ml/minute/1.73m2
  2. Breast Feeding of infants under 11 lb (5 kg)
  • Mechanism
  1. Synthetic hydroxynaphthoquinone with antiprotozoal activity
  2. Blocks mitochondrial electron transport at complex 3 of the respiratory chain of protozoa
    1. Inhibits Pyrimidine synthesis (and therefore protozoal DNA synthesis)
  1. Adults (and children age >13 years)
    1. Prophylaxis: 1500 mg orally daily with food
    2. Treatment: 750 mg orally twice daily with food for 21 days
  1. Atovaquone is taken in combination with either Sulfadiazine or pyrimethanine-leucovorin
  2. Adults (off-label)
    1. Acute: 1500 mg orally twice daily with food for 6 weeks or more
    2. Chronic: 750 to 1500 mg orally with food twice daily
  • Dosing
  • Babesiosis (Mild to Moderate Disease, Off-Label Use)
  1. Taken in combination with Azithromycin (high dose Azithromycin if Immunocompromised)
  2. Adult: 750 mg orally every 12 hours with food
  3. Child: 20 mg/kg (up to 750 mg) orally every 12 hours with food for 7 to 10 days
  1. See Atovaquone/Proguanil (Malarone)
  • Precautions
  • Poor absorption
  1. Take with food (fatty meal) to ensure absorption
  2. Up to 10% of patients still may not absorb Mepron
  3. Repeat dose if Vomiting occurs within one hour of treatment in adults (within 30 minutes for children)
  4. Tablets may be crushed and mixed with 10 ml water if unable to swallow tablets
  • Efficacy
  • HIV
  1. Not as clinically active as Bactrim
  2. Pneumocystis Pneumonia treatment Failure rate: 17%
    1. Contrast with 6% for Bactrim
  • Adverse Effects
  1. Less dose-limiting adverse reactions than Bactrim
    1. Atovaquone: 7%
    2. Bactrim: 20%
  2. Rash
  3. Abdominal Pain
  4. Nausea or Vomiting
  5. Diarrhea
  6. Headache
  7. Mild Liver Function Test abnormalities
  • Safety
  1. Pregnancy Category C
  2. Unknown safety in Lactation
    1. Contraindicated in Breast Feeding of infants under 11 lb (5 kg)
  • Drug Interactions
  1. Reduced plasma levels of Atovaquone (and decreased efficacy)
    1. Efavirenz (avoid)
    2. Rifampin (avoid)
    3. Rifabutin
    4. Rifapentine
    5. Tetracycline
    6. Metoclopramide (Reglan)
  • Resources
  1. Atovaquone Suspension (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2445304e-4b4e-4358-b098-31f3c49c52ef
  • References
  1. (2000) Med Lett Drugs Ther 42(1093):109-12 [PubMed]